Fix redundant subexpression in Generators and iterators example in doc

#3222
`jq 'def range(init; upto; by): def _range: if (by > 0 and . < upto) or (by < 0 and . > upto) then ., ((.+by)|_range) else . end; if by == 0 then init else init|_range end | select((by > 0 and . < upto) or (by < 0 and . > upto)); range(0; 10; 3)'`
Can be simplified and corrected to:
`jq 'def range(init; upto; by): def _range: if (by > 0 and . < upto) or (by < 0 and . > upto) then ., ((.+by)|_range) else empty end; if init == upto then empty elif by == 0 then init else init|_range end; range(0; 10; 3)'`

Author: jhcarl0814

docs/content/manual/dev/manual.yml

@@ -3223,9 +3223,8 @@ sections:
                     def _range:
                         if (by > 0 and . < upto) or (by < 0 and . > upto)
                         then ., ((.+by)|_range)
-                        else . end;
-                    if by == 0 then init else init|_range end |
-                    select((by > 0 and . < upto) or (by < 0 and . > upto));
+                        else empty end;
+                    if init == upto then empty elif by==0 then init else init|_range end;
                 range(0; 10; 3)'
             input: 'null'
             output: ['0', '3', '6', '9']